The Coronary Drug Project is a five year study on the effect of anti-lipidemic drugs (estrogens in two dosages, nicrotinic acid, dextrothyroxin, clofibrate) on patients who have suffered a myocardial infarction. By lowering the cholesterol level it is hoped to reduce the death rate in heart patients by 25%. Patients are males between the ages of thirty and sixty-four who have had a proven myocardial infarction. The program is a double blind study and includes 8,341 participants in fifty-three research centers across the United States. All of the drugs are administered orally in capsule form. Initially, the patients were given a thorough medical examination, chest x-ray and various blood tests. The patients have been seen and examined on a monthly basis for the first visits. After the sixth month the visits are scheduled at four month intervals until completion of the program. Laboratory tests are repeated at regular intervals. A certain number of the group is held on placebo as a control for the five year period. In November 1972 aspirin was added to the study medication of the Coronary Drug Project to test its effectiveness in reducing mortality and morbidity in men who have had a documented myocardial infarction.